Transport Transports Canada Canada TP 7245E



# AIRWORTHINESS DIRECTIVE

The following airworthiness directive (AD) may be applicable to an aircraft which our records indicate is registered in your na me. ADs are issued pursuant to Canadian Aviation Regulation (CAR) 521 Division X . Pursuant to CAR 605.84 and the further details of CAR Standard 625, Appendix H , the continuing airworthiness of a Canadian registered aircraft is contingent upon compliance with all applicable ADs. Failure to comply with the requirements of an AD may invalidate the flight authorization of the aircraft. Alternative means of compliance shall be applied for in accordance with CAR 605.84 and the above-referenced Standard

. This AD has been issued b y the Continuin g Airworthiness Division ( AARDG ) , National Aircraft Certification Branch, Trans p ort Canada, Ottawa, tele p hone 613 952-4357.

Pursuant to CAR 202.51 the registered owner of a Canadian aircraft shall, within seven days, notify the Minister in writing of any change of his or her name or address. To request a change of address, contact the Civil Aviation Communicat ions Centre (AARC) at Place de Ville, Ottawa, Ontario K1A 0N8 , or 1-800-305-2059 , or www.tc.gc.ca/civilaviation/communications/centre/ addr ess.asp 2 4-0022 ( 01-2005 ) 1/2 No

. CF-2011-29R1 Issue Date 24 May 2012

Number: CF-2011-29R1 Subject: Hydraulic Accumulators – Screw Cap/End Cap Failure Effective: 7 June 2012 Revision: Supersedes Airworthiness Directive CF-2011-29, dated 02 August 2011 Applicability: Bombardier Inc. DHC-8 Aeroplan e, Series 100, 200 and 300, Serial Numbers, 003 and subsequent Compliance: As indicated below, unless already accomplished. Background: Seven cases of on-ground hydraulic accumulator screw cap or end cap failure have been experienced on CL-600-2B19 (CRJ) aeroplanes, resulting in loss of the associated hydraulic system and high-energy impact damage to adjacent systems and structure. To date, the lowest number of flight cycles a ccumulated at the time of failure has been 6991. Although there have been no failures to date on any DHC-8 aeroplanes, similar accumulators to those installed on the CL-600-2B19, Part Numbers (P/N) 08-60162-001 and 08-60162-002 (Parking Brake Accumulator), ar e installed on the aeroplanes listed in the Applicability section of this directive. A detailed analysis of the syst ems and structure in the potentia l line of trajectory of a failed screw cap/end cap for the accumulato r has been conducted. It has identified that the worst-case scenarios would be the lo ss of number 2 hydraulic system, and damage to aeroplane structures. This AD gives instructions to determine t he part number and serial number of the existing parking brake accumulator, and where applicable, to replace the accumulator. Revision 1 of this AD mandates the insta llation of restraint devices around the parking brake accumulator end caps to hold them in place in the event of an end cap failure. Corrective Actions: Part I - Replacement of Parking Brake Accumulator Within 2000 hours air time or 12 months, whichev er occurs first, from the effective date of the original issue of this AD (18 August 2011):
A. Determine the part number and serial number of the parking brake accumulator in accordance with the Accomplishment Instru ctions of Bombardier Service Bulletin (SB) 8-32-170, dated 25 February 2011, or later revision approved by the Chief, Continuing Airworthiness, Transport Canada.
B. For accumulators that do not hav e P/N 08-60162-001 or 08-60162-002, proceed to Part III of this AD.No. N ° CF-2011-29R1 2/2

C. For accumulator with P/N 08-60162-001 or 08-60162-002:
1. If the serial number is listed in the Table of paragraph 3.B.(2) of the above-mentioned SB, proceed to Part III of this AD.
2. If the serial number is not listed in the Table paragraph 3.B.(2) of the above-mentioned SB, replace the accumulator in accordance with the Accomplishment Instructions of the above-mentioned SB, or if applicable, Bombardier SB 8-32-172, dated 15 March 2011, or later revision approved by the Chief, Continuing Airworthiness, Transpor t Canada. Proceed to Part III of this AD. Part II - Spare Parts As of the effective date of the origi nal issue of this AD (18 August 2011), no replacement/spare accumulator with P/ N 08-60162-001 or 08-60162-002 is permitted to be installed on any aeroplane unless its serial number is listed in paragraph 3.B.(2) of Bombardier SB 8-132-170, dated 25 February 2011, or later revision approved by the Chief, Continuing Airworthiness, Transport Canada. Part III - Installation of Restraint Devices around Parking Brake Accumulator End Caps Within 6000 hours air time or 36 months, whichever occurs first, from the effective date of this AD, install restraint devices ar ound the parking brake accumulator end caps (ModSum 8Q101901) in accordance with Bombardier SB 8-32-169, Revision A, dated 16 December 2011, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. Incorporation of ModSum 8Q101901 in accor dance with Bombardier SB 8-32-169, Initial Issue, dated 25 November 2011, also meets t he requirements of Part III of this AD. Authorization: For the Minister of Transport, Infrastructure and Communities 

### ORIGINAL SIGNED BY Derek Ferguson Chief, Continuing Airworthiness Contact: Miss Helen Tsai, Continuing Airworthiness, Ottawa, telephone 613-952-4357, facsimile 613-996-9178 or e-mail ADs@tc.gc.ca or any Transport Canada Centre.